Organic coatings are not provided presently in the production of steel pipes used for transporting liquids and gases for the purpose of protecting the pipes against corrosion. Consequently, even in the corrosion plant, particularly during storage, the pipes become corroded which corrosion is even greater during shipping of the pipes to the wholesalers and users thereof. Such corrosion is particularly pronounced in open air storage.
Water readily dissolves a small amount of oxygen from the atmosphere and this, when condenced on the surface of the pipes, becomes highly corrosive. Consequently, such pipes have to be thoroughly cleaned before they can be painted.
Attempts to provide an organic coating on the pipes during the final stage of production thereof have not been satisfactory and it has not been possible to obtain protection for an adequate period of time. The known coatings have a tendency to blister and separate after a short period of time under the stress of reactions caused by the water and oxygen permeating through the coating and between the coating and the pipe because of insufficient adhesion between the coating and the pipe surface.